污泥停留时间对新型A^(2)/O工艺联合生物滤池深度处理城镇废水的探究

Research on Advanced Treatment of Urban Wastewater by New A^(2)/O Process Combined with Biofilter by Sludge Retention Time

为探究污泥停留时间(SRT)对新型A^(2)/O联合生物滤池工艺深度处理城镇低C/N效能的影响,以实际低C/N废水为探究对象,构建了中试规模的A^(2)/O联合BAF工艺,通过调控不同SRT,在室温环境下比较新型处理工艺对生物脱氮除磷及污泥特征的影响。结果表明,SRT延长对COD去除影响不明显,但提高了NH_(4)^(+)-N和PO_(4)^(3-)-P的去除率,SRT延长至16 d时,NH_(4)^(+)-N和PO_(4)^(3-)-P的去除率分别高达94.6%~96.8%和94.5%~95.3%,均高于SRT为10 d。SRT延长提高了污泥浓度并导致VSS/TSS增加,此外,SRT适当延长改善了污泥沉降性,提高了胞外聚合物含量,尤其当SRT为14 d时,EPS含量高达60.5~62.3 mg/g,蛋白质(PN)/多糖(PS)提高至1.59~1.71。本研究结果对新型A^(2)/O联合BAF的应用提供了一定数据支撑与理论依据。

In order to explore the effect of sludge retention time(SRT)on the advanced treatment efficiency of urban low C/N by the new A^(2)/O combined biofilter process,taking the actual low C/N Wastewater as the research object,an A^(2)/O combined BAF process was constructed.By adjusting different SRT,the effects of the new treatment process on biological nitrogen and phosphorus removal and sludge characteristics were compared at room temperature.The results show that SRT prolongation has no obvious effect on COD removal,but improves the removal efficiency of NH_(4)^(+)-N and PO_(4)^(3-)-P.when SRT is prolonged to 16 days,the removal efficiencies of NH_(4)^(+)-N and PO_(4)^(3-)-P were 94.6%~96.8%and 94.5%~95.3%,respectively,which were higher than those of SRT for 10 days.The prolongation of SRT increased the sludge concentration and led to the increase of VSS/TSS.In addition,the appropriate prolongation of SRT improved the sludge settleability and the content of extracellular polymer.Especially when SRT was 14 days,the content of EPS was as high as 60.5~62.3 mg/g and the content of protein(PN)/polysaccharide(PS)was increased to 1.59~1.71.The results of this study provide some data support and theoretical basis for the application of the new A^(2)/O-BAF system.